/*
 * Copyright 2008-2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.appengine.twitter.infrastructure.persistent.jpa;

import javax.persistence.EntityManager;
import javax.persistence.EntityTransaction;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

import com.google.inject.Inject;

/**
 *
 * @author politics wang
 * @since Apr 27, 2009
 *
 */
public class JpaTransactionInterceptor implements MethodInterceptor {

	@Inject
	private EntityManager entityManager;
	
	@Override
	public Object invoke(MethodInvocation invocation) throws Throwable {
		EntityTransaction transaction = entityManager.getTransaction();
		transaction.begin();
		try {
			Object result = invocation.proceed();
			transaction.commit();
			return result;
		} catch (RuntimeException e) {
			transaction.setRollbackOnly();
			throw e;
		} 
	}

}
